中国科学院云南天文台机构知识库

望远镜的仪器偏振效应主要由金属镜面的反射偏振引起，是当前高精度天文偏振测量面临的主要技术问题。为了消除仪器偏振对偏振测量精度的影响，在实验室对金属镀膜材料的偏振特性进行精确全面的测量研究显得至关重要。针对保护铝膜提出一种偏振特性测量方法，该方法使用两种光电调制方式对保护铝膜的缪勒（Mueller）矩阵关键元素进行直接测量，并基于双层膜的结构模型，使用多入射角多波长的测量数据在不依赖色散模型以及参数假设的情况下反演光学参数。反演结果与传统方法得到的结果一致，同时本文方法能够对偏振特性进行更好的表征。

The instrument polarization effect of the telescope, which is mainly caused by the reflection polarization effect of metal coatings on mirrors, is the principal technical problem facing the current highprecision astronomical polarimetry. It is essential to perform accurate and comprehensive measurements and research on the polarization properties of metal coating materials in the laboratory in order to eliminate the influence of instrument polarization on the accuracy of polarimetry. This paper proposes a polarization properties measurement method for the protected aluminum coating. This method can directly measure the key elements of the Mueller matrix of the protected aluminum coating by two photoelectric modulations at a multiple-angle-of-incidence spectrum. This method also retrieves the optical parameters based on the doublelayer model without dispersion model and parameter assumptions. The retrieval results of the method in this paper are consistent with those obtained by traditional methods, and the method in this paper can fully characterize the polarization properties.